长期贮藏大豆分离蛋白溶解性下降原因探讨（一)--大豆分离蛋白中微量油脂氧化的影响.docVIP

  长期贮藏大豆分离蛋白溶解性下降原因探 讨（一)——大豆分离蛋白中微量油脂氧化的 影响# 5 10 15 李祖胤1，曾茂茂1，何志勇1，黄小林2，陈洁1** （1. 江南大学食品学院，江南大学食品科学与技术国家重点实验室，江苏 无锡 214122； 2. 益海-嘉里集团食品技术研究所，河北 秦皇岛 066206） 摘要：为了探寻大豆分离蛋白（SPI）在长期贮藏过程中溶解性不断下降的原因，论文研究 了 SPI 中微量油脂存在的影响。制备了 SPI、含 2%未氧化大豆油 SPI 和含 2%氧化大豆油的 SPI 三组样品，采用真空包装，在贮藏 12 周过程中定期测定样品的溶解度、蛋白羰基、表 面巯基、总巯基以及自由氨基等性质。结果表明在贮藏过程中所有 SPI 的溶解性均有不同程 度的降低，其中含油脂氧化的样品 SPI 溶解度的下降最快且溶解度最低。三组样品在贮藏期 间的羰基、总巯基、自由氨基含量变化几乎无差别，但空白 SPI 的表面自由巯基含量始终高 于含有未氧化大豆油的 SPI 和含氧化大豆油的 SPI（P 0.05）。研究结果表明大豆蛋白贮 藏期间发生了氧化反应，氧化油脂可以促进溶解度下降的加速，但是氧化油脂本身不是导致 蛋白质氧化的唯一影响因素，导致大豆蛋白贮藏过程溶解度下降的原因比较复杂，需要进一 步深入研究。 关键词：大豆分离蛋白；油脂氧化；溶解度；真空包装 中图分类号：TS20 20 Solubility Decreasing of Soy Protein Isolate during Long-term Storage (One) ——Effects of Lipid Oxidation in SPI LI Zuyin1, ZENG Maomao1, HE Zhiyong1, HUANG Xiaolin2, CHEN Jie1 25 30 35 40 (1. State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, JiangSu WuXi 214122; 2. Food Technology Research Institute, Yihai-Kerry Oils Grains Group, HeBei QinHuangDao 066206) Abstract: This paper studies trace lipids impact on solubility decrease of soy protein isolate (SPI) in the process of SPIs long-term storage. Three groups of SPI sample including SPI control , SPI with 2% non-oxidized soybean oil, and SPI with 2% oxidized soybean oil respectively were prepared and then vacuum sealed. During the 12 weeks storage, several properties had been measured regularly, which included solubility, protein carbonyl content, surface free sulfhydryl group content, total sulfhydryl group content, and free amino group content. It was showed that the solubility of three groups of SPI sample decreased in varying degree, solubility of SPI with 2% non-oxidized soybean oil decreased fastest and its final solubility was lowest in three groups of sample. There was no significant difference in protein carbonyl content, total sulfhydryl group content, and free amino group content among three groups of sample during storage, but surface free